Marine navigation is a process of piloting a vessel to a destination in a safe and expeditious manner. While sophisticated electronic equipment is available to aid in the navigation of larger vessels, the majority of mariners continue to navigate by using external reference marks.
A mark is any conspicuous object, natural or man-made, which has utility in establishing the position of a vessel or otherwise acting as a navigational aid. To be an effective navigational aid, each mark must be specifically identified and its position accurately known. Buoys, both lighted and unlighted, lighthouses and lightships are artificial marks designed and erected specifically to function as aids to navigation.
Buoys are the most numerous of all artificial aids to navigation. Buoys can function as daymarks based upon their shape, color and number. Some buoys, particularly those identifying turning points and channels, underwater obstructions, or mooring, docking or slip facilities, are provided with lights to facilitate night time navigation. Buoys may also incorporate horns, bells, whistles or radio transmitters as navigational signals.
Signal buoys require an internal power source to operate the lighting system. Batteries are typically utilized as the power source for buoys on the basis of cost and maintenance considerations. Batteries are typically hardwired into the signal circuitry of the buoy so that the signal source is continually draining energy from the battery.
Mooring, docking or slip facilities likewise require some type of signal source to facilitate nighttime use. The location of the facility or other factors may make it impractical to run a power line for continuous nighttime energization of the signal source. In addition, continuously operated signal sources used with mooring, docking or slip facilities may have a negative impact on navigation inasmuch as these facilities may not be marked on navigational charts, thereby providing a source of confusion for mariners. Therefore, as a practical matter steady-state signal sources used with mooring, docking or slip facilities are typically battery powered and manually activated for nighttime operation.
Battery systems, however, are inherently limited in that the constant power drain upon the battery causes it to become depleted in a short time. A depleted battery cannot effectively function as a power source, and therefore batteries for buoys or docking facilities must be replaced at periodic intervals. Not only is such periodic replacement time consuming, but a navigational hazard exists when any buoy remains unpowered for any length of time. Alternatively, an expensive solar recharging system or cabling must be used to maintain adequate power.
Although individual buoys and buoy networks are maintained by governmental organizations such as the United States Coast Guard, a need exists for a buoy device which may be used for private applications. Such a buoy device should have a configuration which is amenable to one person operations such as buoy emplacement and/or removal, which facilitates in situ servicing, and the buoy device should be reliable, inexpensive and suitable for prolonged use in the marine environment.
In addition, the buoy device should be configured for selective activation. Since the buoy devices may be used in or near lighted environments, the buoy device should provide a distinctive signal which may be readily identified in such environments.